Many different designs of equipment exist for the purpose of physical exercise and physical therapy. One such type, stair climbing machines, or steppers, simulate climbing stairs or steps. With such machine designs known in the industry, the user typically places his or her feet on a pair of pedals and begins to alternately raise his or her legs as if he or she were climbing a flight of stairs. The pedals respond by raising and applying a load resistance which the user must overcome to lower the pedal. The amount of resistance is determined by the weight and/or fitness level of the user. Steppers are known to provide a superior low impact workout for therapy, rehabilitation or cardiovascular conditioning for the amount of time spent by the user on the machine.
One problem with stair climbing machines known in the art is that such steppers require the user to be standing in order to operate the machines. This limitation restricts usage to those who are physically capable of standing during exercise and are thus less than optimal for physical therapy and rehabilitation use. A need, therefore exists for a stepper type exercise device which can be operated in a seated position by those who are unable to stand.
Alternatively, people who are less fit have been known to find stair climbing machines to be too difficult to operate for extended periods of time. In such cases, workouts tend to be shortened, thereby also reducing the aerobic benefit of the workout. A need, therefore, also exists for a stepper type exercise device which allows users who are less physically fit to achieve a sustained cardiovascular workout.
A related limitation is that since the user is in a standing position, the user can effectively use less than his or her body weight alone to overcome the resistance required to raise the pedal. In this manner, the aerobic benefit of the workout is reduced. In addition, it has been known in the art that persons of low body weight sometimes cannot drive known stepper exercise devices because they can exert no more down force than their body weight. As a result, a need exists for a stepper type exercise device which is not responsive to the weight of the user.